A browser is a software application that executes on a data processing system and provides an interface through which a user or another application can request and receive content. For example, a user can input a Uniform Resource Locator (URL) of a website into a browser, the browser accesses a server of the website corresponding to the URL, receives content from the server, and presents the content to the user. As another example, an application invokes a browser to use the browser as an interface to receive inputs into the application and to provide the application outputs.
A browser maintains a cache. A browser cache is a portion of a local storage at the data processing system where the browser is executing, in which the browser saves content items (items) that the browser expects to reuse. For example, if a user accesses a particular website every day, the browser may save some graphical images from the website content into the browser cache so that the browser does not have to spend time obtaining the graphics repeatedly at each access to the website.
A browser cache enables the browser to improve a user experience by locally supplying some previously saved items locally without the latency of data communications over data networks in obtaining those items. As an example, by using a browser cache, the browser can load a webpage faster because only a part of the webpage has to be obtained from a server over a network, and the remaining part is reused from the browser cache at the local data processing system. As another example, a browser can cache the inputs supplied by a user during a previous use of a form, and auto-fill the form by reusing the cached inputs during a subsequent access to the form.
Browsers also execute in mobile devices, such as smartphones, tablet computers, and wearable devices. Presently, the amount of computing resources, including an amount of data storage space, that is available on mobile devices is significantly less than the amount of comparable computing resources that is available on other data processing systems. Consequently, although a browser can maintain a browser cache on a mobile device, the size of the browser cache is significantly smaller than on other data processing systems, such as laptop and desktop computers.